import pygame
from pygame.locals import *
from sys import exit
import random
# 变量
path = 'resources/images/' # 图片保存的路径
index = 0 # 小鸟动画切换的列表下标
y = 300 # 小鸟的上下位置信息
x = 0
g = [300,300,300,300,300]
# 初始化
pygame.init()
screen = pygame.display.set_mode((800, 600)) # 用pygame生成800*600的窗口
pygame.display.set_caption('flappy bird') # 设置标题
bg = pygame.image.load(path + 'bg_day.png') # 根据文件路径和文件名加载图片
bg = pygame.transform.smoothscale(bg, (800, 600)) # 缩放图片大小
birds = [ # 加载三张小鸟图片存放到列表中
    pygame.image.load(
        path + '0.png'),
    pygame.image.load(
        path + '1.png'),
    pygame.image.load(
        path + '2.png')]
gold = pygame.image.load(path + 'gold1.png')
pygame.key.set_repeat(1, 3) # 设置按键一次后延迟1毫秒，必须间隔1毫秒才能摁键
# 运行时
while True:
    for event in pygame.event.get(): 
        if event.type == QUIT:  # 如果收到退出事件，则退出程序
            exit()
        elif event.type == KEYDOWN:  # 如果有按键按下
            key = event.key
            if key == K_SPACE:  # 如果按下空格键
                y = y - 5  # 小鸟向上移动

    screen.blit(bg, (0, 0))  # 将背景图片绘制到窗口上
    screen.blit(birds[index], (x, y))  # 将小鸟图片绘制到窗口上
    for i in range(5):
         screen.blit(gold, (200+i*120, g[i]))
    y = y + 2  # 小鸟向下移动，模拟重力
    x = x+2
    if x>800:
        x = 0
        for i in range(5):
            g[i] = random.randint(200,400)
    if index == 2:  # 如果动画下标等于2
        index = 0  # 重置动画下标
    else:
        index = index + 1  # 否则，动画下标加1

    pygame.display.update()  # 更新窗口显示